Medical imaging devices provide an important diagnostic tool for many medical applications. One example of a medical imaging device is an ultrasound scanner. Ultrasound scans are carried out by transmitting high frequency ultrasonic sound into a human body and received and processing reflections of the transmitted sound in order to create an image of an organ or other structure in the body.
For diagnostic purposes, a medical professional performs an ultrasound scan using a hand-held probe (or more commonly referred to as a transducer) that is placed directly on and moved over the surface of the body. Essentially, the transducer transmits sound waves into the body and receives echoing waves that reflect from internal organs, fluids and tissues. The reflected waves are converted to corresponding electrical pulses that are transmitted to an electronic analyser, and displayed by a computer, which in turn creates a real-time image on a monitor.
Cardiac ultrasound, or echocardiogram, uses standard ultrasound technique to image two-dimensional slices of the heart. An echocardiogram allows a medical professional to analyse the heart beating and to visualise the structures of the heart in order to monitor the state of the heart and to diagnose cardiovascular diseases.
There are two main types of echocardiogram, namely, a transthoracic echocardiogram (TTE), and a transoesophageal echocardiogram (known as TEE or TOE).
TTE is a standard non-invasive procedure and is performed by placing the transducer on the chest wall, aiming an ultrasound beam through the chest and to the heart. Similarly, the transducer records the sound wave echoes as they reflect off internal structures of the patient's chest. In this procedure, the lungs and ribs may obscure the view, and a small amount of intravenous dye may be applied to improve the images.
Although TTE is considered a highly accurate procedure, the accuracy can be reduced because of obesity, chronic obstructive pulmonary disease, or chest-wall deformities. In these circumstances, TOE is recommended. In a TOE procedure, a flexible tube containing a transducer is guided down the patient's throat and into the lower part of the oesophagus. This procedure can allow a clearer two-dimensional echocardiogram of the heart.
As echocardiography becomes a widely used diagnostic tool, training and accreditation in echocardiography has also become vitally important. Training in echocardiography includes instruction in the basic aspects of ultrasound, performing echocardiographic examination to integrate understanding of three-dimensional cardiac anatomy, interpreting two-dimensional (2D) screen images and learning to build a mental model of the heart from multiple 2D images.
Thus, it is desirable to provide a realistic training device for training medical professionals in the use of echocardiography equipment and in the interpretation of resulting 2D ultrasound images.
A similar need can also arise in relation to other types of medical imaging device, such as magnetic resonance imaging (MRI) scanners, X-ray devices, and so on.